Steam generator for automotive vehicles



1933- W. D. LA MONT STEAM GENERATOR FOR AUTOMOTIVE VEHICLES Filed July28, 1927 4 Sheets-Sheet l INVENTOR #4405? DOUGLAS L/Wm/T ATTORNEY5 Aug,1, W33. w. D. LA MONT STEAM GENERATOR FOR AUTOMOTIVE VEHICLES 4Sheets-Sheet 2 INVENTOR /VAZ me fia/ams 1/; /7o/vr ATTORNEY) unlllwllunull Filed July 28, 1927 Aug, 1, 1933. w. D. LA MONT STEAM GENERATORFOR AUTOMOTIVE VEHICLES- Filed July 28,1927 4 Sheets-Sheet 5 OOOOOOOD KQRNN INVENTOR M44715? DOUGLAS Z/i/70/V7' Aug. 1, 1933. w. D. LA MONT1,920,907

STEAM GENERATOR FOR AUTOMOTIVE VEHICLES I Filed July 28, 1927 4Sheets-Sheet 4 fag/5? Patented Aug. 1, 1933 STEM GENERATOR FORAUTOMOTEVE VEHICLES Walter Douglas lLa Mont, Larchmont, N. Y., as-

signor to La Mont Corporation, New York, N. Y., a Corporation of NewYork Application July 28, 1927.

(Cl. 186l) 7 Elaims.

This invention relates to processes and apparatus in which steam isgenerated in tubes of relatively small diameter as compared with watertubes andfire tubes commonly used in commercial boilers.

In my United States Patent No. 1,545,668, July 14, 1925, and in mycopending application, Serial No. 79,096, filed January 4, 1926, I havedisclosed tubes into which the water to be evapo- 0 rated is introducedin quantities greater than the generating capacity of a tube but lessthan sufiicient to fill the tube and through which the generated steamand unevaporated water move towards the discharge end thereof withprovisions for separating the steam from the water and continuouslyreturning the water to the receiving end of a tube. In said patent andapplication the generating elements or tubes are arranged so that thelevel of the discharge end 9 is lower than the receiving end, usinggravity to aid.in the flow of water through the tubes, and maintain afilm of water on the surface of the tubes opposite to that exposed tothe heat. Such arrangements increase the steam generating efficiency ofboilers to which they are applied, whether the tubes are of relativelysmall diameter or are of the size now in general use. In my copendingapplication, Serial No. 162,770, filed January 22, 1927, for instance, Ihave shown the invention applied to fire tube and wa ter tube boilers ofexisting types.

I have discovered, however, that gravity flow is not a necessarycondition to the generation of steam involving what may be brieflycalled the La Mont principle as disclosed in said patent andapplicalion. In fact, the tubes may be horizontal or may be inclinedwith the receiving end of the tube lower than the discharge end.

4 In tubes so arranged, one condition is that the stantially horizontalposition or in a position where the receiving end is below the dischargeend, that the inner surfaces of the tube throughout its entire lengthare constantly wetted. In

the tubes that I have thus far used, the inside diameter has beenapproximately of an inch, although for some uses smaller tubes wouldseem to be even better and possibly somewhat larger tubes may also beused. i

5 'Another condition is that the water be introduced into the receivingend of a tube in a quantity greater than the evaporating capacity of thetube and that the excess water he with-i drawn from the tube at such arate that the 5 quantity of water flowing through the tube is tubesshall be of such a diameter when in a sub- Serial No. 209,02i

constantly less than suflicient to fill the tube, but at all timesgreater than the generating capacity thereof. Or stated in another Way,the quantity of heat received and size of the tube and the quantity ofwater introduced should be so related that both steam and water fiowthrough the tubes from the receiving end thereof with such turbulencyand velocity that the inner surface of the tube is substantiallyconstantly wetted throughout with a film of water and that at all timesthe tube is free from hydraulic pressure such as would cause steamlocking or would interfere with the freedom of flow so that there is nodanger of the tube burning out. The invention finds many usefulapplications, as for instance, in the generation of steam for automotivevehicles such as rail cars, locomotives, automobiles, including trucks,and in such applications the generating tubes are arranged in asubstantially horizontal position.

As applied to locomotives, the invention offers advantages over presentmethods of generating steam since it will aiiord greater steamgenerating capacity for the same or less weight and since locomotives atthe present time are necessarily limited to certain clearances andpossibly weight, any increase in power without increasing weight or sizeis a distinct advantage.

In respect of other automotive vehicles such as trucks, coaches andpleasure cars, the steam motor has many well known advantages notpossessed by the gasoline engine. Automobiles which have heretoforeemployed steam as a motive power have usually relied upon so-calledflash boilers, that is to say, boilers in which all of the waterinjected into the boiler is immediately converted into steam, or boilersin which the water is boiled in substantial masses. The difiiculty ofaccurately and reliably controlling flash boilers has been a seriousobjection to their use and in the mass boiler type there has beendifficulties with the formation of scale, often resulting in burn-outs.

By the use of the present invention, it is possible to generate steam ata sufficiently rapid rate and under simpler controls than is possiblewith the older type of boilers, thereby gaining the advantages of steampower in vehicles of this sort. Preferably, the La Mont generating tubesare arranged lengthwise of the vehicle and underneath the body thereofand extend for a substantial portion of the length of the vehicle.

The invention and its applications will be better understood by moredetailed consideration of 11 0 the several embodiments illustrated byway of r the examples, in the accompanying drawings, which drawings,however, are more or less schematic and illustrate practical ways ofapplying the principles of the invention without including many detailswhich would, of course, be supplied in practice by the designer andengineer for the more convenient and automatic control of variousfunctions.

Referring to the drawings- Figure 1 is a side elevation showing more orless diagrammatically an automotive vehicle having the invention appliedthereto;

Figure 2 is a section on line 2-2 of Figure 1;

Figure 3 is a section on line 3-3 of Figurel;

Figure 4 is a sectional view showing a somewhat difierent arrangement ofthe casing for the tubes to provide insulation and also to permitcirculation of air, which is thereby heated before it is delivered tothe combustion chamber;

Figure 4 is a modification of the construction shown in Figure 4;

Figure 5 is an enlarged view of the crosswise arranged insulation cellsshown in Figure 1;

Figure 6 is an enlarged view of a modified form of means for subdividingthe casing enclosing the tube casing proper to provide for thecirculation around the tube casing;

Figure 7 is an enlarged view of one of the intake headers and intakemanifold;

Figure 8 is an enlarged view of a discharge header showing itsconnection with the pot wherein the stream and water are separated;

Figure 9 is a side elevation of a somewhat modified arrangementembodying the invention;

Figure 10 is a section on line 1010 of Figure 9;

Figure 11 is a section on line 11--11 of Figure 9; Figure 12 is a topview partly in section of the form shown in Figure 9; and

Figure 13 is a diagrammatic view showing one way in which the variousparts may be co-ordinated and controlled.

Referring to Figure 1, the frame of the vehicle may be utilized tosupport a casing for the steam generating elements. This casing is shownat 1 and extends from front to rear of the vehicle and preferably theunder and upper portions are formed each of two plates separated by aninsulating space. In the embodiment shown in Figure 1, the plates areseparated by partitions 2, Figure 5, running transversely of the frameand providing dead air spaces. These partitions are preferably separatedfrom the frame plates by strips 3 of heat-insulating material. Thecasing 1 is closed at the front by a plate 4 but the rear 5 is open andcovered by a screen, through which the exhaust combustion gases flow.The usual hood is somewhat modified and consists of an inner casing 6and outer casing 7, as shown in Figures 1 and 3, thus providing a spacetherebetween through which air may fiow to be utilized in promotingcombustion. As shown, the combustion chamber occupies the major portionsof the hood space and thus provides a combustion chamber of ample size.Not all of this space, however, need be thus utilized but onlysufficient for the purpose of producing combustion gases at asufficiently high temperature and in the desired volume. A fan 8suitably supported on the front portion of the outer casing 7 forces airinto and around the spacebetween the casings 6 and 7. The combustionfuel is supplied through a nozzle shown conventionally at 9.' Suitablemeans, not shown, are provided for burning the fuel within the casing orchamber 6, the flow of air being around the walls of the casing 6 andbetween it and the casing 7, suitable passages being provided so thatthe air enters alongside of the combustion nozzle 9. The hot gases thencome in direct contact with the steam generating elements 10 and afterpassing lengthwise of the tubes are discharged through the screen 5 atthe rear end of the vehicle.

The tubes 10 constitute the steam generating elements and are suitablysupported within the frame and between the upper and lower membersthereof. Several sets of tubes are shown arranged one above the other(Figures 1, 2 and 3) and each set of tubes is supplied with water forsteam generation by a distributing tube 11 carried by a header 12. Thisdistributing tube is shown in enlarged detail in Figure 7 and issemicircular in form with small orifices, one registering with eachgenerating tube 10. For convenience of assemblage the headers 12 haveholes bored therethrough and the end of each tube is expanded into theheader. The distributing tube 11 may then be inserted into the headerfrom one end thereof and plugs 13 are then inserted into the holeopposite the tube end. In this way steam-tight joints are provided andflow of steam and water in one direction assured.

The tubes 10 are of relatively small diameter, those which I have usedbeing of an inch outside diameter and /g inch inside diameter. Thetubes, however, have limits as to size dictated by the followingconsiderations:

In general, tubes as small as possible are desirable because they willstand higher steam pressures with a thinner wall, than large tubes. Theyare therefore lighter and less expensive. on the other hand, where thetubes are exposed to radiant heat and where the advantage of closespacing of the tubes does not enter so much as a factor, since the heattransferred takes place mainly due to the elevation of the temperatureof the heated body, somewhat larger tubes are desirable to provide forthe introduction of a large amount of water necessitated by thecorresponding high evaporation under the action of radiant heat. The useof a larger tube permits a larger orifice in the distributing tube,which is desirable to avoid the danger of clogging and insuring theintroduction into the tube of suflicient water in excess of theevaporating capacity of the tube. The tube, however, must not be solarge as to interfere with the proper propagation of the film by meansof the steam and water fiow, since in a tube of too great diameter thereis danger of hydraulic action, resulting in steam pockets with too largea surface of the tube unwetted and corresponding danger of burning.

When convection gases are used, as small a tube as possible is desiredin order that a great number of tubes closely spaced may occupy a givencross section, thus providing for concentration of the heat surface inthe cross section of the gas passage, thus increasing the rate of heattransfer. Another advantage in smallness of tube is the increase ofheating surface obtained with as short a tube as possible. This isespecially desirable where there is limitation of length of tube. Asmall tube under convection conditions may likewise be used because theevaporation is not so great as under radiant heat conditions andtherefore the amount of water necessary to be introduced into the tubesis relatively smaller and even though the orifice in the tube is alsosmaller there is less danger of clogging. It is apparent. however, thatthe limit of smallness is reached when the orifice in the distributingtube orated by the tube.

The invention therefore is not limited to any exact size of tube butwith due regard to the con ditions just outlined, should be relativelysmall.

The water for the generation of steam in the construction shown inFigure 1 is supplied to the intake distributing tube 11 in quantity lessthan sufiicient to fill the tubes but greater than the steam generatingcapacity of the tubes and by reason of the small orifices in the intakemanifold the water is distributed in .proper proportion to all thetubes. The water supply is obtained from a tank 14 connected by a standpipe 15 to a water distributing header 16, from which run branch pipes17 for supplying each intake or distributing tube 11, of which four areshown in Figure 1. It is, of course, to be understood that the number oftubes will vary according to the power requirements of the particularvehicle upon which they are used. A pipe 18 also connects the header 16to a pump 19 which constantly supplies the necessary head of water tothe tubes 11, the size of the pump being so calculated that water in aproper quantity is delivered. Due in part to the'force of the waterinjected through the orifices in the tubes 11 and in part to theexpansive force of the steam formed in the generating tubes, steam andwater flow through the tubes to the rear or discharge end thereof withsuch velocity and interaction due to the process of ebullition in thesmall tubes used, that the inner surface of the tubes is constantlywetted and steam is rapidly formed and discharged from the water filmformed on the tube surface. Steam and water are discharged into a pot20, where the water is taken up by the pump and returned to the intakemanifold and the separated steam passes into a pipe 21 to a throttlevalve 22. When the throttle valve is opened steam passes through a pipe23 to the engine 24 suitably supported as by a bracket 25 depending fromthe vehicle frame and by the rear axle of the vehicle. Other forms ofsupport may, of course, be used. The exhaust steam from the engine flowsalong pipe 26 upwardly through a pipe 2'7 to a condenser 28. A pump 29connected by a pipe 30 to the distributing header 16 delivers thecondensed steam thereto.

In order to equalize pressure in the pot 20 and supply tank 14, a smallpipe 31 connecting the two is provided, or a pipe with a restrictedportion, as shown at 58, Figure 1.

With the piping arrangement as shown, when the pump 19 stops, the tubes10 are filled with water from the tank 14. As soon, however, as the pumpstarts again the tank 14 begins to fill, due to the restricted orificesin the intake manifolds. When it is necessary to supply additional waterto the system this may be conveniently done, through the tank 14, whichis provided with a cap 32 for this purpose and the pipe 15 and pipe 31are each supplied with a valve to enable the tank 14 to be entirely shutoff from the system when it is being filled. Nor- 'mally both valves areopen. I

The operation will be apparent from what has been already stated but itmay be briefly summarized as follows: The fuel to be burned enteringthrough the nozzle 9 is supplied by the fan with air for its combustionand the combustion gases after passing over the tubes 10 and heating'them to the desired steam generating temperature, pass out at theopening 5. The tubes being of small diameter and of suitable length andlikewise being closely spaced absorb the heat rapidly and efiicientlyfrom the gases when the latter pass over them at high velocity,

and therefore comparatively little heat is wasted in the exit gases.

The water supplied by the pump 19 to the intake manifolds enters theseveral headers and is rapidly converted into steam as it passes alongthe tubes 10, the steam being separated from the water in the pot 20,the unevaporated water being returned again to the headers. The steamutilized in the engine is passed through the condenser and the condensedsteam again also returned to the headers. The amount of water that needsto be supplied to the system is only that due to leakages which withproper design may be, and preferably is, very small.

The pump 19 is designed to be operated at sufiicient pressure tomaintain the desired head of water in the tank 14, but even if thispressure should be a little greater than necessary, a small amount ofwater will be carried over to the pot 20, but only a small amount, dueto the restriction 58 in the connection 31.

The insulation of the tube space both at the .bottom and top, as shownin Figure 1 and described above, is only one of a number of forms whichmight be utilized. Another form of cells is shown in Figure 6 and thesemay run either transversely providing dead air space, or they may runlongitudinally. With the form of partitioning wherein the cells runlongitudinally in-. stead of transversely of the frame, provision may.

be made for passing the air taken in by the fan through the casingbefore it enters the combustion chamber, thereby imparting heat to theair and effecting cooling of the casing plates, thereby preventingradiation loss, the heat thus absorbed being returned to the combustionspace.

In Figure 4 is shown another arrangement consisting of twolongitudinally celled casings outside of the casing carrying thegenerating elements. The inner passages in this figure are designated as33 and outer ones as 34. The air supplied by the fan may be made tocirculate first through the outer passages and then through the innerones and thence to the combustion chamber or in some cases a reversecirculation may be used, that is to say, through the inner passagesfirst and then through the outer ones and thence to the combustionchamber. Other arrangements may'also be used. For instance, some of thecells may be made smaller than others, as illustrated in Figure 4 andthese may be closed against passage of air, thus providing dead airspaces at suitable intervals or these spaces may be filled withinsulation. The closure may be permanent, or dampers may be used in someor all of the cells to control the draft. Still other arrangements maybe employed. w The modification shown in Figure 9 does not have acondenser and hence a larger water supply is necessary than in the formof device shown in Figure 1. In this figure the frame of the vehicleconsisting of channel bars is utilized to support the steam generatingelements which are located in a casing having a lower member 35 and anupper member 36, each of which may and preferably does consist of alower and upper plate between which insulating material is placed, orcirculation cells such as shown in Figures 4 and 6 may be used. Thechannel bars of the vehicle frame may constitute the sides of thiscasing. In this form of device, the hood of the automobile is supportedas usual by the frame and the frame at its forward portion is formedinto a combus- 5 tion chamber indicated by the numeral 37, and

having a burner 38 suitably located therein. Suitable means not shown,but which may be similar to those shown and described in connection withFigure 1, may supply air for combustion, if dcsired. The heated gases,in the form of arrangement shown in Figure 9, likewise come immediatelyinto contact with the tubes 10, and flow along the chamber formed by themembers 35 and 36 to the rear end of the vehicle where they exhaust intothe atmosphere. The tubes 10 are of the same type as illustrated in thefirst described form and they likewise are supplied with intakemanifolds of the same construction already described. The rear end ofthe tubes, however, instead of running into a transversely extendingpot, as shown in Figure 1, enter a discharge header 39 shown in enlargedview in Figure 8, which header is connected with a vertical pot 40wherein the steam and water are separated, the steam going through athrottle controlled pipe 41 to the steam chest 42 of the engine 43 whilethe water entering the pct 40 passes through pump 44 and by way of pipe45 back to the intake headers. Since no condenser is used, the supply ofwater is carried in a tank 4'7 occupying the hood space, which tank isconnected at its lower portion by a valved pipe 48 with the pot 40. Asmall equalizing pipe 49 connects the upper portion of the supply tank4'7 with the upper portion of the pot 40, a valve 50 also being providedin this pipe, which valve and also the valve 51 in the pipe 48, may beclosed when it is desired to supply additional water through the openingclosed by the cap 52. The engine is supported by a bracket 53 dependingfrom the vehicle frame and by the rear axle, as in the first describedform.

Although in the above described embodiments the flow of steam in thetubes is longitudinal of the vehicle, it is nevertheless within thespirit of the invention to arrange the tubes so that the flow of steamtherein is transverse of the vehicle. Such an arrangement is madepossible by reason of the small size of tubes which may be usedaccording to the principles of the invention, and by reason of theirsmall size more of them may be placed in a given space. Therefore asuflicient length may be available in the width of a vehicle to providefor suificient steam generating action. The gases, however, flowlongitudinally, as in the forms described above.

Referringnow to Figure 13, which shows diagrammatically the severalcontrols it will be assumed that the vehicle is stationary and that nofuel is being supplied and no air forced through by the fan. The steamgenerating elements 10, however, are filled with water.

Upon movement of a control lever 60 pivoted at 61 a link 62 rigidlyconnected to a portion 68 of the lever 60 rocks the bell crank lever 63about its pivot and opens the valve 64 to admit fuel to the combustionchamber. This fuel may consist of any suitable liquid, such as crude oilor kerosene, which may be burned in any well known manner. Movement ofthe portion 68 of the lever 60 also closes an electric circuit through amotor 65 connected by a belt or otherwise for operating the circulationpump 19. The circuit for the motor may be traced as follows: startingwith battery A, the current flows through the wire 66-67 to the shaft 61or to a conducting collar on the shaft,

thence along the arm 68 which is also of conducting material and whicharm at this time engages the contact member 69. From 69 the currentflows along wire 70-'71 to the motor 65. Returning, the current flowsalong wire 72-73 back to the battery. The arm 68 also makes electricalcontact with another contact piece 74 which supplies current throughwire '75 to a sparking device 76 within the combustion chamber to ignitethe fuel, a suitable sparking coil 7'? being provided in the circuit.

The initial movement of lever 60 in addition to establishing the severalcircuits already described and substantially simultaneously therewithalso closes a third electrical circuit by the arm 68 coming in contactwith an electrically conducting member '78, to which is connected a wire'79-80 leading to a rheostat 81. An arm 82 stands normally in electricalcontact with one of the rheostat points and the current flows throughthis arm to wire 83 to the fan 8. All of the above described operationstake place when the lever 60 is moved from the position shown in Figure1, to a position coincident with a second lever 60a. It is to beunderstood, however, that the starting of the circulation pump, the fanand the supply of fuel and its ignition while all taking place duringthe initial movement of the lever 60, do not necessarily occursimultaneously, as it is preferable to arrange for the proper lag orlead in starting the several instrumentalities. Preferably thecirculation pump is started first followed by starting of the fan andignition of the fuel. It is of course, obvious that this order may bevaried.

When the lever 60 is moved as described, the pump 19 has been started,fuel has been introduced into the combustion chamber and ignited, thefan circulates air for combustion and forces the heated gases over andalong the generating elements, causing steam to be generated.

To start the engine, the lever 60a is moved in a clockwise direction,which lever operates through a link 84 on a second lever 85 controllingthe throttle valve 22. Steam is then admitted from the steam pot 20through pipes 21 and 23 to the engine 24.

The pump 29 which takes water from the condenser and discharges it intothe water distributing header 16 is operated by a belt on the engineshaft so that upon starting of the engine, the condenser water iscirculated.

If the lever 60 has been operated to perform its various functions andthe lever 60a not operated, the result would be the generation of steamin the tubes 10, but no use would be made of it. A safety valve 86 isprovided for emergency but in order not to waste steam unnecessarily acontrol is provided whereby the supply of fuel is cut down and the fanslowed down under these circumstances. This is brought about through arise of pressure in the pct 20. A pipe 87 leading from the upper portionof the pot conveys pressure to a piston 88 to move a rod 89 connected toan arm forming a bell crank with the arm 82 to cut in resistance to thefan circuit, the movement being opposed by a compression spring 89.Likewise the pressure acts through a diaphragm. control 90 to cut downthe fuel supply The order in which the different elements are broughtinto action, may likewise be varied.

For instance, with the tubes 10 full of water, the combustion may firstbe started and steam generated, as in the ordinary water tube boiler.The steam so generated may be used to operate the water circulating pump65. Since the steam generated under these conditions would collectmostly in the tank 14, a connection from this tank would lead to a steamengine which would be substituted for the electric motor 19.

What is claimed as new is:

1. The combination in an automotive vehicle, a combustion chamber andsteam generating elements extending longitudinally throughout asubstantial portion of the length thereof, a casing enclosing saidelements through which casing the heating gases may pass, alongitudinally celled casing outside said first mentioned casing andthrough which the air to be used for combustion passes before entrancethereof into the combustion chamber.

2. The combination in an automotive vehicle having a body, of steamgenerating elements extending under the body and throughout asubstantial portion of the length thereof and means for positivelymaintaining circulation through said elements of water in quantitygreater than the steam generating capacity thereof but less thansumcient to fill said elements.

3. In combination with a body and hood of an automotive vehicle, ofsteam generating elements extending outside of the hood, and acombustion chamber occupying a substantial portion of the hood forsupplying the heat for said elements.

4. The combination in an automotive vehicle having a body and having aframe provided with a portion extending beyond said body, of steamgenerating elements arranged adjacent to the body, a combustion chamberarranged adjacent said extended portion of the frame, and means forcausing the combustion gases to pass from the combustion chamber oversaid steam generating elements.

5. The combination with an automotive vehicle having a hood, of steamgenerating elements having at least a part of their length extendingoutside said hood along a portion of the vehicle, and a combustionchamber in the hood for supplying the heat for said elements.

6. The combination with an automotive vehicle of a plurality of steamgenerating tubes having at least a part of their lengths extendinggenerally parallel to each other and longitudinally of the vehicle, acombustion chamber for supplying the steam generating heat for saidtubes and so located in relation thereto as to deliver the gases ofcombustion to said lonigtudinally extending part of the tubes, and acasing surrounding said part of the tubes and connected to saidcombustion chamber so as to cause the heating gases to passlongitudinally of the vehicle lengthwise over said part of the tubes.

7. In combination with an automotive vehicle for normally horizontaltravel, a combustion chamber mounted in the vehicle, a casing mounted inthe vehicle and providing a gas passage having its lonigtudinal extentnormally horizontal, said casing at one end thereof being connected tosaid combustion chamber so as to receive the combustion gases from thecombustion chamber and to confine their flow lengthwise of the passage,a set of tubes mounted in said gas passage and having their lengthsextending generally parallel to the lonigtudinal extent of the passage,whereby the flow of fluid through the tube is normally substantiallyhorir'ontal and the flow of gases from the combustion chamber is alongthe length of the tubes toward the end thereof remote from thecombustion chamber.

WALTER DOUGLAS LA MONT.

